diff --git a/setup.py b/setup.py
index 9ed029c681bd5cacabf8ed0114217530b83c02ae..f401b2e06166bf1c256f32e61d9dbb6830a35379 100644
--- a/setup.py
+++ b/setup.py
@@ -87,7 +87,9 @@ if not GSL_DIR:
     )
 BINARY_C_DIR = os.getenv("BINARY_C", None)
 if not BINARY_C_DIR:
-    print("\n\n****\n**** Error: the BINARY_C environment variable is not set.\n**** This environment variable should point to the root of your binary_c\n**** installation (i.e. the directory you acquired from the repository).\n**** Aborting setup.\n****\n\n")
+    print(
+        "\n\n****\n**** Error: the BINARY_C environment variable is not set.\n**** This environment variable should point to the root of your binary_c\n**** installation (i.e. the directory you acquired from the repository).\n**** Aborting setup.\n****\n\n"
+    )
     quit(1)
 
 # TODO: write code to know exact parent directory of this file.